Re: EMI guard bands
"Tania Grant" wrote: > > Amund, > > My minimum criteria and recommendation has always been at least 6dB. > However, how many engineering managers, upon finding a 1.5 dB margin in > their favor, rule "ship it"! Although in some markets, there are customers who require -6dB under the Class A limit. Although if I had it my way, I'd make it about -10dB under the limit. - Doug McKean --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: Sometimes product safety just isn't enough
robertj wrote: > > Ever since I saw this, I have been wondering what's going on in the mind of this guy: > - doesn't have a clue > - can probably get away with this > - my tools are in good shape, everything's OK Well, he is working next to a wet bar. Doug McKean --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: surges on 24VAC
I read in !emc-pstc that Jennifer Banh wrote (in ) about 'surges on 24VAC', on Mon, 17 Dec 2001: >I am currently trying to test a product of ours that falls under 50082-1 >generic standard for light industrial equipment. If this is a new product, you should be using EN61000-6-1. Look at clause 8. It is indeed not reasonable to apply the mains surge test to a 24 V power port. Make sure you explain this fully in your technical file. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk After swimming across the Hellespont, I felt like a Hero. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: surges on 24VAC
The surge test in 61000-4-5 is for testing for the effects of a lightning remnants getting into the mains or an I-O/Telecom line. Some product committees require surge tests to any power port, regardless of the source of that power, but it seems to me that unless the 24V power is from a distributed DC system coming from outside a structure where a lightning remnant could get in, lightning testing doesn't make much sense. We it WOULD make sense is to unit that converts the AC into 24V!. It seems there are such things as distributed DC systems (i.e. the telephone system in the US is a 48V DC system bring DC into homes and buildings from wires strung on telephone poles) and for these systems, lightning testing might make sense -- hence no provision in the standard that makes DC systems exempt from testing. Hope this is helpful... Mike Hopkins Thermo KeyTek -Original Message- From: Jennifer Banh [mailto:jb...@bb-elec.com] Sent: Monday, December 17, 2001 2:44 PM To: emc-p...@majordomo.ieee.org Subject: surges on 24VAC Hello everyone, I am currently trying to test a product of ours that falls under 50082-1 generic standard for light industrial equipment. Our problem is that we have a 24VAC power input port. The generic standard calls out for EN 61000-4-5 on AC power input ports. After looking at EN 61000-4-5 it seems that it is intended for AC mains voltages, but I couldn't find anything that says a 24VAC input is exempt from this test. I am looking for outside opinions on whether this test is truly applicable. Thanks, Jennifer Banh BTW, we already tried just testing to the spec, and failed. Any suggestions on how to protect against this test would also be appreciated. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: Thermal effects on EMC and Earth Leakage
How much of a temperature increase are we talking about, how much do emissions increase, and what frequency(s) increase in emissions? - Doug McKean --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
SV: Non-compliant product put into EU marked
Lazy... yes maybe or they might have trouble with coordination of the different processes as development, pre-tests, development, final tests, all files completed, ship it to the marked, etc But I assume that they will not put it into the marked, because they are not allowed. So they might be lazy but they won't get trouble with the authorities. Amund -Opprinnelig melding- Fra: John Juhasz [mailto:jjuh...@fiberoptions.com] Sendt: 17. desember 2001 20:55 Til: 'Tania Grant'; am...@westin-emission.no; emc-p...@majordomo.ieee.org Emne: RE: Non-compliant product put into EU marked Hmmm . . . Sounds to me that due to the limited marketing of the product, the manufacturer doesn't want to absorb the expense of compliance testing. Generally speaking, while a compliant test report (especially from a good independent lab)holds weight, as has been noted on several occassions testing is not the only route. Can the manufacturer produce justification that the original compliance has not been affected by the modifications? It doesn't appear to me that the manufacturer is TOTALLY ignorant, just lazy. As they are not applying the mark, they cannot be accused of falsley claiming compliance - but that doesn't absolve them from having to comply with the Directives applicable to their product. IMHO they're playing with fire . . . John Juhasz Fiber Options Bohemia, NY (The opinions expressed here, for what they're worth, are mine alone) -Original Message- From: Tania Grant [mailto:taniagr...@msn.com] Sent: Monday, December 17, 2001 1:33 PM To: am...@westin-emission.no; emc-p...@majordomo.ieee.org Subject: Re: Non-compliant product put into EU marked Is the manufacturer serious, or completely ignorant? If serious, I would disassociate from them as much as possible. If merely ignorant, and you have some sort of association with them, I would recommend that you educate them fully. Another thought, -- is this product slated for mass distribution, even for only a month, or is it going to another location or a particular customer for some special in-house use or application? What does this customer think? Are they aware, and do they agree to this? The Directives do have special provisions for certain special applications where non-compliant (or is it merely "untested" !) product can be shipped to Europe, but I believe that under those circumstances, the name of the manufacturer and product model name or designation has to be "published" broadly in the EU. I don't remember the details. If anyone can shed more light, that would be very nice. taniagr...@msn.com - Original Message - From: To: Sent: Sunday, December 16, 2001 2:06 PM Subject: Non-compliant product put into EU marked > > Hi all, > > You place a radio product into the EU marked with the following status: > > - Not been EMC, radio or safety tested (the previous model was tested and > compliant, major modifications have later been implemented) > - The product will only be in the marked for a time limiting period ( 1 > month) > - During the time limiting period it will be operating as in a normal > condition > - No CE mark on the product and no DoC > > I mean that you can't do this. You have to confirm that you fulfil the EMC, > radio and safety requirements, DoC in place, even that the product just will > be in the marked for 1 month and thereafter withdrawal. > > Any other comments from the list members ? > > Best regards > Amund Westin, Oslo/Norway --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer on
SV: Non-compliant product put into EU marked
"Special temporary authorization" or "experimental license" sounds good to me, but in this case it is only a regular radio equipment which has been re-designed and installed in a well known radio system. But I agree and ask the same question as you do Don, is there a route for "special temporary authorization" or "experimental license" for a specific customer location? Amund -Opprinnelig melding- Fra: djumbdenst...@tycoint.com [mailto:djumbdenst...@tycoint.com] Sendt: 17. desember 2001 22:37 Til: am...@westin-emission.no; emc-p...@majordomo.ieee.org; taniagr...@msn.com Emne: RE: Non-compliant product put into EU marked Is there a route for "special temporary authorization" or "experimental license" for a specific customer location? This may be on a spectrum authority (SA) by SA basis. "Just do it!" may be a fine logo for selling shoes, but does not work in legal arenas. Don Umbdenstock Sensormatic Electronics Tyco International > -- > From: Tania Grant[SMTP:taniagr...@msn.com] > Reply To: Tania Grant > Sent: Monday, December 17, 2001 1:33 PM > To: am...@westin-emission.no; emc-p...@majordomo.ieee.org > Subject: Re: Non-compliant product put into EU marked > > > Is the manufacturer serious, or completely ignorant? > > If serious, I would disassociate from them as much as possible. If merely > ignorant, and you have some sort of association with them, I would > recommend > that you educate them fully. > > Another thought, -- is this product slated for mass distribution, even for > only a month, or is it going to another location or a particular customer > for some special in-house use or application? What does this customer > think? Are they aware, and do they agree to this? The Directives do > have > special provisions for certain special applications where non-compliant > (or > is it merely "untested" !) product can be shipped to Europe, but I > believe > that under those circumstances, the name of the manufacturer and product > model name or designation has to be "published" broadly in the EU. I > don't > remember the details. If anyone can shed more light, that would be very > nice. > > taniagr...@msn.com > > - Original Message - > From: > To: > Sent: Sunday, December 16, 2001 2:06 PM > Subject: Non-compliant product put into EU marked > > > > > > Hi all, > > > > You place a radio product into the EU marked with the following status: > > > > - Not been EMC, radio or safety tested (the previous model was tested > and > > compliant, major modifications have later been implemented) > > - The product will only be in the marked for a time limiting period ( 1 > > month) > > - During the time limiting period it will be operating as in a normal > > condition > > - No CE mark on the product and no DoC > > > > I mean that you can't do this. You have to confirm that you fulfil the > EMC, > > radio and safety requirements, DoC in place, even that the product just > will > > be in the marked for 1 month and thereafter withdrawal. > > > > Any other comments from the list members ? > > > > Best regards > > Amund Westin, Oslo/Norway > > > > > > --- > > This message is from the IEEE EMC Society Product Safety > > Technical Committee emc-pstc discussion list. > > > > Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ > > > > To cancel your subscription, send mail to: > > majord...@ieee.org > > with the single line: > > unsubscribe emc-pstc > > > > For help, send mail to the list administrators: > > Michael Garretson:pstc_ad...@garretson.org > > Dave Healddavehe...@mediaone.net > > > > For policy questions, send mail to: > > Richard Nute: ri...@ieee.org > > Jim Bacher: j.bac...@ieee.org > > > > All emc-pstc postings are archived and searchable on the web at: > > No longer online until our new server is brought online and the old > messages are imported into the new server. > > > > --- > This message is from the IEEE EMC Society Product Safety > Technical Committee emc-pstc discussion list. > > Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ > > To cancel your subscription, send mail to: > majord...@ieee.org > with the single line: > unsubscribe emc-pstc > > For help, send mail to the list administrators: > Michael Garretson:pstc_ad...@garretson.org > Dave Healddavehe...@mediaone.net > > For policy questions, send mail to: > Richard Nute: ri...@ieee.org > Jim Bacher: j.bac...@ieee.org > > All emc-pstc postings are archived and searchable on the web at: > No longer online until our new server is brought online and the old > messages are imported into the new server. > --- This message is from the IEEE EMC Society Product Safety Technical Committee
SV: Non-compliant product put into EU marked
As far as I know the product shall be produced in a large scale. The reason for putting it on the marked for a time limiting period is (again as far as I know) to run the product ( beta version) in a test installation and thereafter will it go through the entire test program (EMC, LVD, etc). It seems that they did not manage to do the testing before the 1 month test period on the field. Again, I feel they are not doing things in the consecutive order and I also think they are no allowed to put in on the marked, even the short period. Amund -Opprinnelig melding- Fra: Tania Grant [mailto:taniagr...@msn.com] Sendt: 17. desember 2001 19:33 Til: am...@westin-emission.no; emc-p...@majordomo.ieee.org Emne: Re: Non-compliant product put into EU marked Is the manufacturer serious, or completely ignorant? If serious, I would disassociate from them as much as possible. If merely ignorant, and you have some sort of association with them, I would recommend that you educate them fully. Another thought, -- is this product slated for mass distribution, even for only a month, or is it going to another location or a particular customer for some special in-house use or application? What does this customer think? Are they aware, and do they agree to this? The Directives do have special provisions for certain special applications where non-compliant (or is it merely "untested" !) product can be shipped to Europe, but I believe that under those circumstances, the name of the manufacturer and product model name or designation has to be "published" broadly in the EU. I don't remember the details. If anyone can shed more light, that would be very nice. taniagr...@msn.com - Original Message - From: To: Sent: Sunday, December 16, 2001 2:06 PM Subject: Non-compliant product put into EU marked > > Hi all, > > You place a radio product into the EU marked with the following status: > > - Not been EMC, radio or safety tested (the previous model was tested and > compliant, major modifications have later been implemented) > - The product will only be in the marked for a time limiting period ( 1 > month) > - During the time limiting period it will be operating as in a normal > condition > - No CE mark on the product and no DoC > > I mean that you can't do this. You have to confirm that you fulfil the EMC, > radio and safety requirements, DoC in place, even that the product just will > be in the marked for 1 month and thereafter withdrawal. > > Any other comments from the list members ? > > Best regards > Amund Westin, Oslo/Norway > > > --- > This message is from the IEEE EMC Society Product Safety > Technical Committee emc-pstc discussion list. > > Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ > > To cancel your subscription, send mail to: > majord...@ieee.org > with the single line: > unsubscribe emc-pstc > > For help, send mail to the list administrators: > Michael Garretson:pstc_ad...@garretson.org > Dave Healddavehe...@mediaone.net > > For policy questions, send mail to: > Richard Nute: ri...@ieee.org > Jim Bacher: j.bac...@ieee.org > > All emc-pstc postings are archived and searchable on the web at: > No longer online until our new server is brought online and the old messages are imported into the new server. > --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: EMI guard bands
Tania and Amund, IMHO, the margin of compliance should be at least equal to or greater than the measurement uncertainty. Measurement uncertainty for radiated emissions is generally in the range of 3 to 4 dB for most labs. Jim Hulbert Pitney Bowes "Tania Grant" To: , Sent by: cc: owner-emc-pstc@majordom Subject: Re: EMI guard bands o.ieee.org 12/17/2001 01:38 PM Please respond to "Tania Grant" Amund, My minimum criteria and recommendation has always been at least 6dB. However, how many engineering managers, upon finding a 1.5 dB margin in their favor, rule "ship it"! Education (repeated brainwashing of as many 'powerful company managers) has been my response;-- but that often takes time. In those cases, there is a written memoranda signed by me explaining why that kind of approach is not correct. taniagr...@msn.com - Original Message - From: To: Sent: Sunday, December 16, 2001 11:20 AM Subject: SV: EMI guard bands > > Cecil, > > When thinking of EMI guard band (margins), I put the following into mind: > 1. variation in production (a couple of dB) > 2. uncertainly during measurements (5-6 dB at lower frequencies like 30MHz) > 3. variation from labs to labs (I don't know 4-6 dB ?? ) > > I think 6-8dB should give you a good feeling. > > Amund > > > > > > > -Opprinnelig melding- > Fra: owner-emc-p...@majordomo.ieee.org > [mailto:owner-emc-p...@majordomo.ieee.org]Pa vegne av > cecil.gitt...@kodak.com > Sendt: 10. desember 2001 13:46 > Til: emc-p...@majordomo.ieee.org > Emne: EMI guard bands > > > > From: Cecil A. Gittens > > I am in the process of putting a document together for products that are > tested for Radiated & Conducted Emissions > that should have a Guard-band of 6 dB for FCC or CISPR22 class A or B. > Does it depend if the product is class A or B? > Does anyone have any pointers or suggestions? > > Thanks. > > > --- > This message is from the IEEE EMC Society Product Safety > Technical Committee emc-pstc discussion list. > > Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ > > To cancel your subscription, send mail to: > majord...@ieee.org > with the single line: > unsubscribe emc-pstc > > For help, send mail to the list administrators: > Michael Garretson:pstc_ad...@garretson.org > Dave Healddavehe...@mediaone.net > > For policy questions, send mail to: > Richard Nute: ri...@ieee.org > Jim Bacher: j.bac...@ieee.org > > All emc-pstc postings are archived and searchable on the web at: > No longer online until our new server is brought online and the old > messages are imported into the new server. > > > --- > This message is from the IEEE EMC Society Product Safety > Technical Committee emc-pstc discussion list. > > Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ > > To cancel your subscription, send mail to: > majord...@ieee.org > with the single line: > unsubscribe emc-pstc > > For help, send mail to the list administrators: > Michael Garretson:pstc_ad...@garretson.org > Dave Healddavehe...@mediaone.net > > For policy questions, send mail to: > Richard Nute: ri...@ieee.org > Jim Bacher: j.bac...@ieee.org > > All emc-pstc postings are archived and searchable on the web at: > No longer online until our new server is brought online and the old messages are imported into the new server. > ---
RE: Non-compliant product put into EU marked
Is there a route for "special temporary authorization" or "experimental license" for a specific customer location? This may be on a spectrum authority (SA) by SA basis. "Just do it!" may be a fine logo for selling shoes, but does not work in legal arenas. Don Umbdenstock Sensormatic Electronics Tyco International > -- > From: Tania Grant[SMTP:taniagr...@msn.com] > Reply To: Tania Grant > Sent: Monday, December 17, 2001 1:33 PM > To: am...@westin-emission.no; emc-p...@majordomo.ieee.org > Subject: Re: Non-compliant product put into EU marked > > > Is the manufacturer serious, or completely ignorant? > > If serious, I would disassociate from them as much as possible. If merely > ignorant, and you have some sort of association with them, I would > recommend > that you educate them fully. > > Another thought, -- is this product slated for mass distribution, even for > only a month, or is it going to another location or a particular customer > for some special in-house use or application? What does this customer > think? Are they aware, and do they agree to this? The Directives do > have > special provisions for certain special applications where non-compliant > (or > is it merely "untested" !) product can be shipped to Europe, but I > believe > that under those circumstances, the name of the manufacturer and product > model name or designation has to be "published" broadly in the EU. I > don't > remember the details. If anyone can shed more light, that would be very > nice. > > taniagr...@msn.com > > - Original Message - > From: > To: > Sent: Sunday, December 16, 2001 2:06 PM > Subject: Non-compliant product put into EU marked > > > > > > Hi all, > > > > You place a radio product into the EU marked with the following status: > > > > - Not been EMC, radio or safety tested (the previous model was tested > and > > compliant, major modifications have later been implemented) > > - The product will only be in the marked for a time limiting period ( 1 > > month) > > - During the time limiting period it will be operating as in a normal > > condition > > - No CE mark on the product and no DoC > > > > I mean that you can't do this. You have to confirm that you fulfil the > EMC, > > radio and safety requirements, DoC in place, even that the product just > will > > be in the marked for 1 month and thereafter withdrawal. > > > > Any other comments from the list members ? > > > > Best regards > > Amund Westin, Oslo/Norway > > > > > > --- > > This message is from the IEEE EMC Society Product Safety > > Technical Committee emc-pstc discussion list. > > > > Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ > > > > To cancel your subscription, send mail to: > > majord...@ieee.org > > with the single line: > > unsubscribe emc-pstc > > > > For help, send mail to the list administrators: > > Michael Garretson:pstc_ad...@garretson.org > > Dave Healddavehe...@mediaone.net > > > > For policy questions, send mail to: > > Richard Nute: ri...@ieee.org > > Jim Bacher: j.bac...@ieee.org > > > > All emc-pstc postings are archived and searchable on the web at: > > No longer online until our new server is brought online and the old > messages are imported into the new server. > > > > --- > This message is from the IEEE EMC Society Product Safety > Technical Committee emc-pstc discussion list. > > Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ > > To cancel your subscription, send mail to: > majord...@ieee.org > with the single line: > unsubscribe emc-pstc > > For help, send mail to the list administrators: > Michael Garretson:pstc_ad...@garretson.org > Dave Healddavehe...@mediaone.net > > For policy questions, send mail to: > Richard Nute: ri...@ieee.org > Jim Bacher: j.bac...@ieee.org > > All emc-pstc postings are archived and searchable on the web at: > No longer online until our new server is brought online and the old > messages are imported into the new server. > --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and th
Re: 2 Phases in North America
As you are well aware, the physics behind acoustics and electromagnetics are very similar. The term overtone definitely has an acoustic pedigree, whereas the term harmonic has been adopted by electrical engineering. But the 1st overtone explicitly contains the info that we are talking about a component at a higher frequency than the fundamental. The term harmonic simply means that the various components are related to each other by ratios of whole numbers, including the number one. The fundamental is the first harmonic. The second harmonic is the first overtone. This seems eminently sensible, intuitively appealing, and as I said previously, these are accepted definitions going back decades in my experience, but likely hundreds of years. Should not be a topic involving lengthy debate. -- >From: bogdan matoga >To: Ken Javor >Cc: Cortland Richmond <72146@compuserve.com>, ieee pstc list >Subject: Re: 2 Phases in North America >Date: Mon, Dec 17, 2001, 1:44 PM > > Ken: > I think that you did not miss too much - my Physics 101 however was over 50 > years ago and harmonics were only > mentioned in acoustics! Now, who wins? > Greetings, > Bogdan. > > Ken Javor wrote: > >> I haven't been following this train but my recollection of definitions from >> Physics 101 more than a quarter century ago is that the fundamental is the >> first harmonic. The first overtone is the second harmonic. These are/were >> accepted definitions. >> >> -- >> >From: Cortland Richmond <72146@compuserve.com> >> >To: bogdan matoga , ieee pstc list >> >Subject: Re: 2 Phases in North America >> >Date: Mon, Dec 17, 2001, 12:04 AM >> > >> >> > >> > If we're smart (are we?) we'll say "fundamental," and let whoever wants to >> > argue what "2nd" means have the arena all to themselves! >> > >> > I would say there are harmonics of the second order, third order, and so >> > on, to which we refer, in short, as the second and third harmonics (and so >> > on). Don't forget, though, where the terms came from; what IS harmonic >> > motion, hmm? >> > >> > Cortland >> > >> > --- >> > This message is from the IEEE EMC Society Product Safety >> > Technical Committee emc-pstc discussion list. >> > >> > Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ >> > >> > To cancel your subscription, send mail to: >> > majord...@ieee.org >> > with the single line: >> > unsubscribe emc-pstc >> > >> > For help, send mail to the list administrators: >> > Michael Garretson:pstc_ad...@garretson.org >> > Dave Healddavehe...@mediaone.net >> > >> > For policy questions, send mail to: >> > Richard Nute: ri...@ieee.org >> > Jim Bacher: j.bac...@ieee.org >> > >> > All emc-pstc postings are archived and searchable on the web at: >> > No longer online until our new server is brought online and the old >> > messages are imported into the new server. >> > >> >> --- >> This message is from the IEEE EMC Society Product Safety >> Technical Committee emc-pstc discussion list. >> >> Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ >> >> To cancel your subscription, send mail to: >> majord...@ieee.org >> with the single line: >> unsubscribe emc-pstc >> >> For help, send mail to the list administrators: >> Michael Garretson:pstc_ad...@garretson.org >> Dave Healddavehe...@mediaone.net >> >> For policy questions, send mail to: >> Richard Nute: ri...@ieee.org >> Jim Bacher: j.bac...@ieee.org >> >> All emc-pstc postings are archived and searchable on the web at: >> No longer online until our new server is brought online and the old > messages are imported into the new server. > > > --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: Three phase delta system in USA
Ghery - He is correct. There are DELTA configured transformers with one phase earthed in the US. This is referred to as "corner grounded." Refer to http://saskpower.apogee.net/foe/ftdttd.asp for a brief on the applications. The site is incomplete (overall), but has some useful information. Regards, Peter L. Tarver, PE Product Safety Manager Sanmina-SCI Homologation Services peter.tar...@sanmina-sci.com -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of Pettit, Ghery Sent: Monday, December 17, 2001 8:01 AM To: 'innova...@t-online.de'; Crabb, John; 'Bill Lawrence'; 'EMC-PSTC Forum' Subject: RE: Three phase delta system in USA Horst, Not correct. From past experience, the 480 VAC 60 Hz delta system runs with all three phases floating. This is also done on ships so that a fault to ground on a single phase does not disrupt the system. Ghery Pettit Intel -Original Message- From: innova...@t-online.de [mailto:innova...@t-online.de] Sent: Monday, December 17, 2001 6:05 AM To: Crabb, John; 'Bill Lawrence'; 'EMC-PSTC Forum' Subject: Three phase delta system in USA I also learned, that there is a three-phase delta system in USA with 500 Vac per phase. One phase (L3) is earthed. Is this system very often used in USA? Is it correct information, that L3 is always earthed and not L1 or L2. Horst Haug -Ursprüngliche Nachricht- Von: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]Im Auftrag von Crabb, John Gesendet: Montag, 17. Dezember 2001 11:28 An: 'Bill Lawrence'; 'EMC-PSTC Forum' Betreff: RE: 2 Phases in North America Bill - you absolutely correct in describing the North American system as "single-phase, 3 wire". After all, that is how it is described in Annex V, Figure V.4 of IEC60950:1999 - and there is NO WAY that IEC TC74 could be wrong, is there ? (especially since the US committee must have voted yes, to include this change, the purpose of which was to educate those of us who weren't too clear on the subject). Fortunately I am on holiday (vacation) from tonight until January 3, so to all our readers, best wishes for the Christmas season, and a happy and prosperous 2002. John Crabb, Development Excellence (Product Safety) , NCR Financial Solutions Group Ltd., Kingsway West, Dundee, Scotland. DD2 3XX E-Mail :john.cr...@scotland.ncr.com Tel: +44 (0)1382-592289 (direct ). Fax +44 (0)1382-622243. VoicePlus 6-341-2289. -Original Message- From: Bill Lawrence [mailto:wlawr...@capecod.net] Sent: 14 December 2001 22:33 To: 'Wagner, John P (John)'; 'Robert Johnson'; 'Cortland Richmond' Cc: 'Barry Esmore'; 'EMC-PSTC Forum' Subject: RE: 2 Phases in North America Two Phase / 5 Wire (4 "hots" and a neutral) was a common power distribution in US cities in the early part of this century. Many early motors are "2-phase" motors. I learned about this when helping with connection of these motors to run on a 3 phase power system via a special "Scott-T" transformer connection. The correct designation for the 120/240 power system described is "Single Phase / 3 Wire". Bill Lawrence --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: 2 Phases in North America
I read in !emc-pstc that lfresea...@aol.com wrote (in <169.5d0f58e.294f6 e...@aol.com>) about '2 Phases in North America', on Mon, 17 Dec 2001: >0 implies nothing ( prehaps 0 ac ) ... therefore the "0th" harmonic is >dc??? That fits with Fourier analysis. > >if a squarewave is made up of "odd" harmonics, we would have to rethink that, >correct? Indeed. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk After swimming across the Hellespont, I felt like a Hero. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: Sometimes product safety just isn't enough
I read in !emc-pstc that oover...@lexmark.com wrote (in <200112171644.LA a08...@interlock2.lexmark.com>) about 'Sometimes product safety just isn't enough', on Mon, 17 Dec 2001: >"There are, however, some winged creatures that walk on all fours that you may >eat: those that have jointed legs for hopping on the ground. >Of these you may eat any kind of locust, katydid, cricket or grasshopper. >But all other winged creatures that have four legs you are to detest." All the creatures mentioned have six legs. What winged creatures have four legs? (Not bats!) ISTR a few moths that have modified front legs, so that they *appear* to have only four. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk After swimming across the Hellespont, I felt like a Hero. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: What happened to the IEC60417 symbol library?
I read in !emc-pstc that POWELL, DOUG wrote (in ) about 'What happened to the IEC60417 symbol library?', on Mon, 17 Dec 2001: > My questions was not >about IEC60617 the Graphical symbol library for use on diagrams (drawings >and schematics). Instead it was about the IEC60417 Graphical symbols for >use on equipment (labels). Go to http://www.iec.ch and search diligently. You will find out how to get access to IEC60417 on line (not free!). -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk After swimming across the Hellespont, I felt like a Hero. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: 2 Phases in North America
John Shinn wrote: > If we refer back to the series, and refer to the n-th term, we > would all be on the same page (and harmonic). And in harmony! Cortland (disclaimer: my views, not Alcatel's!) --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: 2 Phases in North America
I read in !emc-pstc that Mike Hopkins wrote (in <49CD487E8BA9D31181190060081C6B8F3BEBE5@COMSERVER>) about '2 Phases in North America', on Mon, 17 Dec 2001: >(I know this is not the convention, but it seems logical: first harmonic is >fundamental plus the fundamental (once); second is the fundamental plus the >fundamental x 2, etc. ). I like it! We shouldn't confuse beginners with this discussion. The fundamental, in electrical engineering, is the 'first harmonic' as well. Musicians or some musicians, AIUI, have a different view. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk After swimming across the Hellespont, I felt like a Hero. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: 2 Phases in North America
This whole issue boils down to semantics and how we count and use numbers. The first issue is what is a harmonic. A harmonic is a multiple of the fundamental. This can be seen when we look at the Fourier series: V(t) = a(0) + a(1)sin(wt) + a(2)sin(wt) + a(3)sin(wt) + ... where a(n) is the magnitude of the n-th term in the series and w is angular frequency (radians/sec) Then the 0-th term would represent any "DC" component present, the 1-th (or 1-st) would represent the fundamental, and the 2-th (or 2-nd) would represent 2 times the fundamental, or the second harmonic, etc. If we refer back to the series, and refer to the n-th term, we would all be on the same page (and harmonic). John Shinn, P.E. -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of lfresea...@aol.com Sent: Monday, December 17, 2001 7:52 AM To: mhopk...@thermokeytek.com; bogda...@pacbell.net; cortland.richm...@alcatel.com Cc: r...@canoga.com; john...@itesafety.com; bar...@melbpc.org.au; emc-p...@majordomo.ieee.org Subject: Re: 2 Phases in North America Mike, I don't go with you on this one... 0 implies nothing ( prehaps 0 ac ) ... therefore the "0th" harmonic is dc??? if a squarewave is made up of "odd" harmonics, we would have to rethink that, correct? Derek. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: Non-compliant product put into EU marked
Hmmm . . . Sounds to me that due to the limited marketing of the product, the manufacturer doesn't want to absorb the expense of compliance testing. Generally speaking, while a compliant test report (especially from a good independent lab)holds weight, as has been noted on several occassions testing is not the only route. Can the manufacturer produce justification that the original compliance has not been affected by the modifications? It doesn't appear to me that the manufacturer is TOTALLY ignorant, just lazy. As they are not applying the mark, they cannot be accused of falsley claiming compliance - but that doesn't absolve them from having to comply with the Directives applicable to their product. IMHO they're playing with fire . . . John Juhasz Fiber Options Bohemia, NY (The opinions expressed here, for what they're worth, are mine alone) -Original Message- From: Tania Grant [mailto:taniagr...@msn.com] Sent: Monday, December 17, 2001 1:33 PM To: am...@westin-emission.no; emc-p...@majordomo.ieee.org Subject: Re: Non-compliant product put into EU marked Is the manufacturer serious, or completely ignorant? If serious, I would disassociate from them as much as possible. If merely ignorant, and you have some sort of association with them, I would recommend that you educate them fully. Another thought, -- is this product slated for mass distribution, even for only a month, or is it going to another location or a particular customer for some special in-house use or application? What does this customer think? Are they aware, and do they agree to this? The Directives do have special provisions for certain special applications where non-compliant (or is it merely "untested" !) product can be shipped to Europe, but I believe that under those circumstances, the name of the manufacturer and product model name or designation has to be "published" broadly in the EU. I don't remember the details. If anyone can shed more light, that would be very nice. taniagr...@msn.com - Original Message - From: To: Sent: Sunday, December 16, 2001 2:06 PM Subject: Non-compliant product put into EU marked > > Hi all, > > You place a radio product into the EU marked with the following status: > > - Not been EMC, radio or safety tested (the previous model was tested and > compliant, major modifications have later been implemented) > - The product will only be in the marked for a time limiting period ( 1 > month) > - During the time limiting period it will be operating as in a normal > condition > - No CE mark on the product and no DoC > > I mean that you can't do this. You have to confirm that you fulfil the EMC, > radio and safety requirements, DoC in place, even that the product just will > be in the marked for 1 month and thereafter withdrawal. > > Any other comments from the list members ? > > Best regards > Amund Westin, Oslo/Norway --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
surges on 24VAC
Hello everyone, I am currently trying to test a product of ours that falls under 50082-1 generic standard for light industrial equipment. Our problem is that we have a 24VAC power input port. The generic standard calls out for EN 61000-4-5 on AC power input ports. After looking at EN 61000-4-5 it seems that it is intended for AC mains voltages, but I couldn't find anything that says a 24VAC input is exempt from this test. I am looking for outside opinions on whether this test is truly applicable. Thanks, Jennifer Banh BTW, we already tried just testing to the spec, and failed. Any suggestions on how to protect against this test would also be appreciated. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: Thermal effects on EMC and Earth Leakage
Have a look at the manufacturer's data sheets for the capacitors, and you'll see spec's or graphs indicating the % capacitance change vs. temperature. This can be substantial for ceramic cap's in particular. I don't know how much of an effect it is for the typical film-type X and Y cap's, but that is likely the source of the change in leakage current. Keep in mind that the EMC performance of a SMPS may be related to many factors, not just X or Y capacitor performance. There are often capacitors located further inside the product that are not X or Y types (and aren't required to be) yet serve an EMC-reduction function, that could be ceramic types with significant value change vs. temperature. There will also be temperature-related changes in electrolytic filter cap's, magnetic components, snubbers, the power semiconductors themselves, etc. Many of these changes may seem subtle in absolute value, but given the impact that parasitics have on EMC, the change could make a big difference. Jim Eichner, P.Eng. Manager, Engineering Services Xantrex Technology Inc. Mobile Power phone: (604) 422-2546 fax: (604) 420-1591 e-mail: jim.eich...@xantrex.com web: www.xantrex.com -Original Message- From: duncan.ho...@snellwilcox.com [mailto:duncan.ho...@snellwilcox.com] Sent: Monday, December 17, 2001 7:59 AM To: emc-p...@majordomo.ieee.org Subject: Thermal effects on EMC and Earth Leakage Group. I am interested to find out peoples opinions on a particular trend we've seen time and time again on most switch mode PSU's. It seems that once a PSU is warm its earth leakage decreases and its EMC emission performance decreases (i.e. it gets noisier). This would suggest that there is some sort of thermal effect, probabaly in the Y caps, that reduces their capacitance. Has anyone done any work in this area or can anyone explain the physics of this change. Is it as simple as expansion of the dielectric or is it more complicated than this? Any thoughts or opinions would be greatly recieved. Many thanks in advance, Duncan Hobbs -- The contents of this communication are confidential to the normal user of the email address to which it was sent. If you have received this email in error, any use, dissemination, forwarding, printing or copying of this email is strictly prohibited. If this is the case, please notify the sender and delete this message. -- --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: 2 Phases in North America
Ken: I think that you did not miss too much - my Physics 101 however was over 50 years ago and harmonics were only mentioned in acoustics! Now, who wins? Greetings, Bogdan. Ken Javor wrote: > I haven't been following this train but my recollection of definitions from > Physics 101 more than a quarter century ago is that the fundamental is the > first harmonic. The first overtone is the second harmonic. These are/were > accepted definitions. > > -- > >From: Cortland Richmond <72146@compuserve.com> > >To: bogdan matoga , ieee pstc list > >Subject: Re: 2 Phases in North America > >Date: Mon, Dec 17, 2001, 12:04 AM > > > > > > > If we're smart (are we?) we'll say "fundamental," and let whoever wants to > > argue what "2nd" means have the arena all to themselves! > > > > I would say there are harmonics of the second order, third order, and so > > on, to which we refer, in short, as the second and third harmonics (and so > > on). Don't forget, though, where the terms came from; what IS harmonic > > motion, hmm? > > > > Cortland > > > > --- > > This message is from the IEEE EMC Society Product Safety > > Technical Committee emc-pstc discussion list. > > > > Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ > > > > To cancel your subscription, send mail to: > > majord...@ieee.org > > with the single line: > > unsubscribe emc-pstc > > > > For help, send mail to the list administrators: > > Michael Garretson:pstc_ad...@garretson.org > > Dave Healddavehe...@mediaone.net > > > > For policy questions, send mail to: > > Richard Nute: ri...@ieee.org > > Jim Bacher: j.bac...@ieee.org > > > > All emc-pstc postings are archived and searchable on the web at: > > No longer online until our new server is brought online and the old > > messages are imported into the new server. > > > > --- > This message is from the IEEE EMC Society Product Safety > Technical Committee emc-pstc discussion list. > > Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ > > To cancel your subscription, send mail to: > majord...@ieee.org > with the single line: > unsubscribe emc-pstc > > For help, send mail to the list administrators: > Michael Garretson:pstc_ad...@garretson.org > Dave Healddavehe...@mediaone.net > > For policy questions, send mail to: > Richard Nute: ri...@ieee.org > Jim Bacher: j.bac...@ieee.org > > All emc-pstc postings are archived and searchable on the web at: > No longer online until our new server is brought online and the old > messages are imported into the new server. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: 2 Phases in North America
Gentlemen: I certainly did not intend to start philosophical contortions! Season's greetings and a harmonic(*) New Year! Bogdan. (*) Now what will this start lfresea...@aol.com wrote: > Mike, > > I don't go with you on this one... > > 0 implies nothing ( prehaps 0 ac ) ... therefore the "0th" harmonic is > dc??? > > if a squarewave is made up of "odd" harmonics, we would have to rethink that, > correct? > > Derek. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: Thermal effects on EMC and Earth Leakage
I can't speculate on the reason for the increase in leakage current; however, I suspect you have a thermal design problem with the switching circuit. I have seen an increase in conducted emissions due to a change of the switching waveform - e.g. rise and fall times and ringing - once the product has reached operating temperature. I have also seen this problem vary from unit to unit due to spurious switching noise on the waveform. Richard Woods Sensormatic Electronics Tyco International -Original Message- From: duncan.ho...@snellwilcox.com [mailto:duncan.ho...@snellwilcox.com] Sent: Monday, December 17, 2001 10:59 AM To: emc-p...@majordomo.ieee.org Subject: Thermal effects on EMC and Earth Leakage Group. I am interested to find out peoples opinions on a particular trend we've seen time and time again on most switch mode PSU's. It seems that once a PSU is warm its earth leakage decreases and its EMC emission performance decreases (i.e. it gets noisier). This would suggest that there is some sort of thermal effect, probabaly in the Y caps, that reduces their capacitance. Has anyone done any work in this area or can anyone explain the physics of this change. Is it as simple as expansion of the dielectric or is it more complicated than this? Any thoughts or opinions would be greatly recieved. Many thanks in advance, Duncan Hobbs -- The contents of this communication are confidential to the normal user of the email address to which it was sent. If you have received this email in error, any use, dissemination, forwarding, printing or copying of this email is strictly prohibited. If this is the case, please notify the sender and delete this message. -- --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: Thermal effects on EMC and Earth Leakage
Duncan First of all, I would think about your sources of EMI and how they can get stronger with your PSU warmed up. Active switches and diodes are EMI sources that can produce more noise when more energy is dissipated by them. The conducting resistance of MOSFETs increase with higher junction temperature. It means more voltage drop in this component and more power for this EMI source. Günter J. Maass EMBRACO S.A. duncan.hobbs@snellwilco x.com To: emc-p...@majordomo.ieee.org Sent by: cc: owner-emc-pstc@majordom Subject: Thermal effects on EMC and Earth Leakage o.ieee.org 17/12/01 13:58 Please respond to duncan.hobbs Group. I am interested to find out peoples opinions on a particular trend we've seen time and time again on most switch mode PSU's. It seems that once a PSU is warm its earth leakage decreases and its EMC emission performance decreases (i.e. it gets noisier). This would suggest that there is some sort of thermal effect, probabaly in the Y caps, that reduces their capacitance. Has anyone done any work in this area or can anyone explain the physics of this change. Is it as simple as expansion of the dielectric or is it more complicated than this? Any thoughts or opinions would be greatly recieved. Many thanks in advance, Duncan Hobbs -- The contents of this communication are confidential to the normal user of the email address to which it was sent. If you have received this email in error, any use, dissemination, forwarding, printing or copying of this email is strictly prohibited. If this is the case, please notify the sender and delete this message. -- --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: EMI guard bands
Amund, My minimum criteria and recommendation has always been at least 6dB. However, how many engineering managers, upon finding a 1.5 dB margin in their favor, rule "ship it"! Education (repeated brainwashing of as many 'powerful company managers) has been my response;-- but that often takes time. In those cases, there is a written memoranda signed by me explaining why that kind of approach is not correct. taniagr...@msn.com - Original Message - From: To: Sent: Sunday, December 16, 2001 11:20 AM Subject: SV: EMI guard bands > > Cecil, > > When thinking of EMI guard band (margins), I put the following into mind: > 1. variation in production (a couple of dB) > 2. uncertainly during measurements (5-6 dB at lower frequencies like 30MHz) > 3. variation from labs to labs (I don't know 4-6 dB ?? ) > > I think 6-8dB should give you a good feeling. > > Amund > > > > > > > -Opprinnelig melding- > Fra: owner-emc-p...@majordomo.ieee.org > [mailto:owner-emc-p...@majordomo.ieee.org]Pa vegne av > cecil.gitt...@kodak.com > Sendt: 10. desember 2001 13:46 > Til: emc-p...@majordomo.ieee.org > Emne: EMI guard bands > > > > From: Cecil A. Gittens > > I am in the process of putting a document together for products that are > tested for Radiated & Conducted Emissions > that should have a Guard-band of 6 dB for FCC or CISPR22 class A or B. > Does it depend if the product is class A or B? > Does anyone have any pointers or suggestions? > > Thanks. > > > --- > This message is from the IEEE EMC Society Product Safety > Technical Committee emc-pstc discussion list. > > Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ > > To cancel your subscription, send mail to: > majord...@ieee.org > with the single line: > unsubscribe emc-pstc > > For help, send mail to the list administrators: > Michael Garretson:pstc_ad...@garretson.org > Dave Healddavehe...@mediaone.net > > For policy questions, send mail to: > Richard Nute: ri...@ieee.org > Jim Bacher: j.bac...@ieee.org > > All emc-pstc postings are archived and searchable on the web at: > No longer online until our new server is brought online and the old > messages are imported into the new server. > > > --- > This message is from the IEEE EMC Society Product Safety > Technical Committee emc-pstc discussion list. > > Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ > > To cancel your subscription, send mail to: > majord...@ieee.org > with the single line: > unsubscribe emc-pstc > > For help, send mail to the list administrators: > Michael Garretson:pstc_ad...@garretson.org > Dave Healddavehe...@mediaone.net > > For policy questions, send mail to: > Richard Nute: ri...@ieee.org > Jim Bacher: j.bac...@ieee.org > > All emc-pstc postings are archived and searchable on the web at: > No longer online until our new server is brought online and the old messages are imported into the new server. > --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: Non-compliant product put into EU marked
Is the manufacturer serious, or completely ignorant? If serious, I would disassociate from them as much as possible. If merely ignorant, and you have some sort of association with them, I would recommend that you educate them fully. Another thought, -- is this product slated for mass distribution, even for only a month, or is it going to another location or a particular customer for some special in-house use or application? What does this customer think? Are they aware, and do they agree to this? The Directives do have special provisions for certain special applications where non-compliant (or is it merely "untested" !) product can be shipped to Europe, but I believe that under those circumstances, the name of the manufacturer and product model name or designation has to be "published" broadly in the EU. I don't remember the details. If anyone can shed more light, that would be very nice. taniagr...@msn.com - Original Message - From: To: Sent: Sunday, December 16, 2001 2:06 PM Subject: Non-compliant product put into EU marked > > Hi all, > > You place a radio product into the EU marked with the following status: > > - Not been EMC, radio or safety tested (the previous model was tested and > compliant, major modifications have later been implemented) > - The product will only be in the marked for a time limiting period ( 1 > month) > - During the time limiting period it will be operating as in a normal > condition > - No CE mark on the product and no DoC > > I mean that you can't do this. You have to confirm that you fulfil the EMC, > radio and safety requirements, DoC in place, even that the product just will > be in the marked for 1 month and thereafter withdrawal. > > Any other comments from the list members ? > > Best regards > Amund Westin, Oslo/Norway > > > --- > This message is from the IEEE EMC Society Product Safety > Technical Committee emc-pstc discussion list. > > Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ > > To cancel your subscription, send mail to: > majord...@ieee.org > with the single line: > unsubscribe emc-pstc > > For help, send mail to the list administrators: > Michael Garretson:pstc_ad...@garretson.org > Dave Healddavehe...@mediaone.net > > For policy questions, send mail to: > Richard Nute: ri...@ieee.org > Jim Bacher: j.bac...@ieee.org > > All emc-pstc postings are archived and searchable on the web at: > No longer online until our new server is brought online and the old messages are imported into the new server. > --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: Sometimes product safety just isn't enough
Ever since I saw this, I have been wondering what's going on in the mind of this guy: - doesn't have a clue - can probably get away with this - my tools are in good shape, everything's OK Bob Johnson ITE Safety -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org] On Behalf Of Robert Johnson Sent: Wednesday, December 12, 2001 1:28 PM To: emc-p...@majordomo.ieee.org Subject: Sometimes product safety just isn't enough I couldn't help passing on this reference to a bit of unforeseeable misuse. http://electrical-contractor.net/ubb/Forum4/HTML/48.html Bob Johnson
RE: Three phase delta system in USA
There are many such local services in the US. The only services you can dependably expect are the 120/240 (center tapped) residential service 120Y208 three phase business/commercial service 277Y480 three phase light industrial service There are many other conventions based on peculiar industries, history or special applications, but the need to address any other service should be subject to negotiation with the customer. These applications are often addressed with local transformers dedicated to the purpose. Most older 500 volt services have made the transition to 480 volt (either delta or wye). 600 volt delta is somewhat common and many new buildings are using multi kV for large motor loads. All premise wiring systems must be earthed except in very rare circumstances such as hospitals, cranes, electrolytic cells, or low voltage lighting. You cannot depend on any convention for either grounding or phase rotation, except that wye and center tapped systems use the center as the neutral or earthed conductor. Once a neutral (grounded conductor) is established, it should be identified throughout the system by insulation color (white, grey or in special circumstances light blue), white hardware (silver, chrome rather than brass), tracer threads, etc. Details of this are addressed in our National Electrical Code NFPA 70. Bob Johnson ITE Safety -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org] On Behalf Of Horst Haug Sent: Monday, December 17, 2001 9:05 AM To: Crabb, John; 'Bill Lawrence'; 'EMC-PSTC Forum' Subject: Three phase delta system in USA I also learned, that there is a three-phase delta system in USA with 500 Vac per phase. One phase (L3) is earthed. Is this system very often used in USA? Is it correct information, that L3 is always earthed and not L1 or L2. Horst Haug
Re: 2 Phases in North America
I can see that this subject hasn't fazed ANYONE. Cortland (speaking, as usual, for myself - and not my employer) --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: What happened to the IEC60417 symbol library?
Hello all, On this topic, there's a fair amount of confusion going on in this group. Which surprises me, since for the most part, people who are involved with regulatory issues are more careful in their reading. My questions was not about IEC60617 the Graphical symbol library for use on diagrams (drawings and schematics). Instead it was about the IEC60417 Graphical symbols for use on equipment (labels). The new online 60617 is not the same as the online 60417 once was. As for copyright, I purchased this document long ago and I make use of it. It's just that it is cellulose-based and not electronic. I often find it much easier to explain myself to various drafting and design types if I can forward a pictorial of the symbol in question. In my original question, I was hoping to find the online resource somewhere else since Dr. Ikeda discontinued his. -doug --- Douglas E. Powell, Compliance Engineer Advanced Energy Industries, Inc. Mail stop: 203024 1626 Sharp Point Drive Ft. Collins, CO 80525 970.407.6410 (phone) 970-407.5410 (fax) mailto:doug.pow...@aei.com --- _ This message, including any attachments, may contain information that is confidential and proprietary information of Advanced Energy Industries, Inc. The dissemination, distribution, use or copying of this message or any of its attachments is strictly prohibited without the express written consent of Advanced Energy Industries, Inc. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: 2 Phases in North America
Electric utilities genreate and distribute 3 phase power. At the load, then, some power conversion strategy is employed to derive 2 phase power. For instance, by adding a secondary winging on a 3 phase transformer on phases A and B with 47% of the winding on phase A and 53% on phase B, the resultant is a voltage lagging phase A by 90 degrees. The turns ratio between primary and secondary is adjusted to get the desired secondary voltage on the "new" phase. This is essentially what capacitor start single phase motors do -- temporarily derive a phase approximately 90 degreees from the single phase, so that there is some rotational torque for starting. Once running, this is no longer necessary and the start winding drops out. On a 2 phase motor, the second phase remains in the circuit. John P. Wagner Regulatory Compliance & Mandatory Standards AVAYA Strategic Standards. 1300 W. 120th Ave, Room B3-D16 Phone/Fax: (303) 538-4241 johnwag...@avaya.com > -- > From: Hans Mellberg[SMTP:emcconsult...@yahoo.com] > Reply To: Hans Mellberg > Sent: Saturday, December 15, 2001 11:00 AM > To: Cortland Richmond; bogda...@pacbell.net > Cc: Robert Johnson; 'Barry Esmore'; 'EMC-PSTC Forum' > Subject: Re: 2 Phases in North America > > > ok folks. This topic needs to be clarified. > > With respect to each other, by definition, two conductors have a > potential > difference at 180 degrees. Period. The 90 degree stuff may pertain to > current but > not to voltage. You would need a four-phase transformer to get 90 > degree phasing and > simply it does not exist. Voltage, is usually measured: wrt ground, > wrt other > reference conductor such as neutral or wrt to another voltage (hot) > conductor. In > some cases, the voltage difference between ground and two other > conductors may be > 120/240 degrees such as in a three phase system. So, no matter how you > measure > voltage it will either be at 120, 180 or 240 degrees wrt to some other > conductor. > > In the US there have been many systems of low voltage (staying below > 480V)distribution yielding the following voltages: > > 480/240/120 > 480/208/120 from three three phase > 480/230/115 single split phase > 230/115 single split phase motor control voltage > 220/110 single split phase older home voltages > 208/120 from three phase > 480/277 (for fluorescent lighting) > 117 (where did this come from? seen in many older HP instruments) > Open Delta (3, 4 or 5 wire, when one is grounded into neutral its > called a > "stinger") > Split phase (three or four wire) > Y (four and five wire) > > Hope this stirrs the pot > > > = > Best Regards > Hans Mellberg > Regulatory Compliance & EMC Design Services Consultant > By the Pacific Coast next to Silicon Valley, > Santa Cruz, CA, USA > 408-507-9694 > > __ > Do You Yahoo!? > Check out Yahoo! Shopping and Yahoo! Auctions for all of > your unique holiday gifts! Buy at http://shopping.yahoo.com > or bid at http://auctions.yahoo.com > > --- > This message is from the IEEE EMC Society Product Safety > Technical Committee emc-pstc discussion list. > > Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ > > To cancel your subscription, send mail to: > majord...@ieee.org > with the single line: > unsubscribe emc-pstc > > For help, send mail to the list administrators: > Michael Garretson:pstc_ad...@garretson.org > Dave Healddavehe...@mediaone.net > > For policy questions, send mail to: > Richard Nute: ri...@ieee.org > Jim Bacher: j.bac...@ieee.org > > All emc-pstc postings are archived and searchable on the web at: > No longer online until our new server is brought online and the > old messages are imported into the new server. >
Re: Sometimes product safety just isn't enough
In the spirit of the season: "John wore clothing made of camel's hair, with a leather belt around his waist, and he ate locust and wild honey." Matthew 3:4, Mark 1:6 "There are, however, some winged creatures that walk on all fours that you may eat: those that have jointed legs for hopping on the ground. Of these you may eat any kind of locust, katydid, cricket or grasshopper. But all other winged creatures that have four legs you are to detest." Leviticus 11:22-23 "Ted Rook" on 12/17/2001 11:07:42 AM Please respond to "Ted Rook" To: "<" cc:(bcc: Oscar Overton/Lex/Lexmark) Subject: Re: Sometimes product safety just isn't enough fortunately we are omnivores and while preferring to dine on the upper branches of the food chain tree nothing prevents homo sapiens sapiens from thriving on the lower branches even though they don't look or smell so pretty, everything's OK so long as our internal pathogen and infection defenses are in good order bon appetit :-) Best Regards Ted Rook, Console Engineering, ext 4659 Please note our new location and phone numbers: Crest Audio Inc, 16-00 Pollitt Drive Fair Lawn, NJ 07410 USA 201 475 4600 telephone receptionist, 8.30 - 5 pm EST. 201 475 4659 direct line w/voice mail, 24 hrs. 201 475 4677 fax, 24 hrs. >>> 17-Dec-01 7:30:45 AM >>> This particular labeling of "Nut" products is not an isolated event. Pick up viturally any container of mixed nuts and it will have a similar warning. Of course don't start reading too many food labels, it can get really scary. FDA's Food Alergen page is: http://www.fda.gov/ora/compliance_ref/cpg/cpgfod/cpg555-250.htm And you thought product safety standards were convoluted and political driven! We won't discuss the pages that address the standards for" "a. Insect Filth and Mold . . . contains an average of 1% or more insect infested and/or moldy pieces by weight. or b. Mammalian Excreta . . . contains an average of 1 milligram or more of mammalian excreta per pound. or c. Foreign Matter . . . contains an average of 1% or more pickings and siftings by weight, (What exactly is "Foreign Matter?) "The following represents the criteria for direct reference seizure: Insect Filth . . . contains an average of 100 or more insect fragments per 25 grams Rodent Filth . . . contains an average of 4 or more rodent hairs per 25 grams." and this is before it gets to the minimum wage food preparation specialist. "Do you want fries with that?" "Robert Macy" on 12/14/2001 04:39:16 PM Please respond to "Robert Macy" To: "James Collum" , emc-pstc%majordomo.ieee@interlock.lexmark.com cc:(bcc: Oscar Overton/Lex/Lexmark) Subject: Re: Sometimes product safety just isn't enough --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: What happened to the IEC60417 symbol library?
The main page for the site is still up, just none of the content we all seek. http://w3.hike.te.chiba-u.ac.jp/iec417/ver2.0/html/index.htm l Regards, Peter L. Tarver, PE Product Safety Manager Sanmina Homologation Services peter.tar...@sanmina.com --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: 2 Phases in North America
Failed on the first try. Let's try again. Peter > -Original Message- > From: Peter Tarver [mailto:peter.tar...@sanmina.com] > Sent: Friday, December 14, 2001 8:57 AM > To: 'EMC-PSTC Forum' > Cc: 'Barry Esmore' > Subject: RE: 2 Phases in North America > > > This is a recurring topic. > > While referred to generally as "single-phase," > two phases, as Bob Johnson indicated, are present > in most homes. This is also called "split-phase." > > I make to representation about the products this > company sells, but there is a depiction of this > power arrangement at > > http://www.itvss.com/pdf/spliti.pdf > > on the first page of the Adobe Acrobat document > (though only one winding of the three-phase, > delta connected transformer is shown). > > Regards, > > Peter L. Tarver, PE > Product Safety Manager > Sanmina Homologation Services > peter.tar...@sanmina.com --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Thermal effects on EMC and Earth Leakage
Group. I am interested to find out peoples opinions on a particular trend we've seen time and time again on most switch mode PSU's. It seems that once a PSU is warm its earth leakage decreases and its EMC emission performance decreases (i.e. it gets noisier). This would suggest that there is some sort of thermal effect, probabaly in the Y caps, that reduces their capacitance. Has anyone done any work in this area or can anyone explain the physics of this change. Is it as simple as expansion of the dielectric or is it more complicated than this? Any thoughts or opinions would be greatly recieved. Many thanks in advance, Duncan Hobbs -- The contents of this communication are confidential to the normal user of the email address to which it was sent. If you have received this email in error, any use, dissemination, forwarding, printing or copying of this email is strictly prohibited. If this is the case, please notify the sender and delete this message. -- --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: Three phase delta system in USA
Horst, Not correct. From past experience, the 480 VAC 60 Hz delta system runs with all three phases floating. This is also done on ships so that a fault to ground on a single phase does not disrupt the system. Ghery Pettit Intel -Original Message- From: innova...@t-online.de [mailto:innova...@t-online.de] Sent: Monday, December 17, 2001 6:05 AM To: Crabb, John; 'Bill Lawrence'; 'EMC-PSTC Forum' Subject: Three phase delta system in USA I also learned, that there is a three-phase delta system in USA with 500 Vac per phase. One phase (L3) is earthed. Is this system very often used in USA? Is it correct information, that L3 is always earthed and not L1 or L2. Horst Haug -Ursprüngliche Nachricht- Von: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]Im Auftrag von Crabb, John Gesendet: Montag, 17. Dezember 2001 11:28 An: 'Bill Lawrence'; 'EMC-PSTC Forum' Betreff: RE: 2 Phases in North America Bill - you absolutely correct in describing the North American system as "single-phase, 3 wire". After all, that is how it is described in Annex V, Figure V.4 of IEC60950:1999 - and there is NO WAY that IEC TC74 could be wrong, is there ? (especially since the US committee must have voted yes, to include this change, the purpose of which was to educate those of us who weren't too clear on the subject). Fortunately I am on holiday (vacation) from tonight until January 3, so to all our readers, best wishes for the Christmas season, and a happy and prosperous 2002. John Crabb, Development Excellence (Product Safety) , NCR Financial Solutions Group Ltd., Kingsway West, Dundee, Scotland. DD2 3XX E-Mail :john.cr...@scotland.ncr.com Tel: +44 (0)1382-592289 (direct ). Fax +44 (0)1382-622243. VoicePlus 6-341-2289. -Original Message- From: Bill Lawrence [mailto:wlawr...@capecod.net] Sent: 14 December 2001 22:33 To: 'Wagner, John P (John)'; 'Robert Johnson'; 'Cortland Richmond' Cc: 'Barry Esmore'; 'EMC-PSTC Forum' Subject: RE: 2 Phases in North America Two Phase / 5 Wire (4 "hots" and a neutral) was a common power distribution in US cities in the early part of this century. Many early motors are "2-phase" motors. I learned about this when helping with connection of these motors to run on a 3 phase power system via a special "Scott-T" transformer connection. The correct designation for the 120/240 power system described is "Single Phase / 3 Wire". Bill Lawrence
Re: 2 Phases in North America
I haven't been following this train but my recollection of definitions from Physics 101 more than a quarter century ago is that the fundamental is the first harmonic. The first overtone is the second harmonic. These are/were accepted definitions. -- >From: Cortland Richmond <72146@compuserve.com> >To: bogdan matoga , ieee pstc list >Subject: Re: 2 Phases in North America >Date: Mon, Dec 17, 2001, 12:04 AM > > > If we're smart (are we?) we'll say "fundamental," and let whoever wants to > argue what "2nd" means have the arena all to themselves! > > I would say there are harmonics of the second order, third order, and so > on, to which we refer, in short, as the second and third harmonics (and so > on). Don't forget, though, where the terms came from; what IS harmonic > motion, hmm? > > Cortland > > --- > This message is from the IEEE EMC Society Product Safety > Technical Committee emc-pstc discussion list. > > Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ > > To cancel your subscription, send mail to: > majord...@ieee.org > with the single line: > unsubscribe emc-pstc > > For help, send mail to the list administrators: > Michael Garretson:pstc_ad...@garretson.org > Dave Healddavehe...@mediaone.net > > For policy questions, send mail to: > Richard Nute: ri...@ieee.org > Jim Bacher: j.bac...@ieee.org > > All emc-pstc postings are archived and searchable on the web at: > No longer online until our new server is brought online and the old > messages are imported into the new server. > --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: Sometimes product safety just isn't enough
fortunately we are omnivores and while preferring to dine on the upper branches of the food chain tree nothing prevents homo sapiens sapiens from thriving on the lower branches even though they don't look or smell so pretty, everything's OK so long as our internal pathogen and infection defenses are in good order bon appetit :-) Best Regards Ted Rook, Console Engineering, ext 4659 Please note our new location and phone numbers: Crest Audio Inc, 16-00 Pollitt Drive Fair Lawn, NJ 07410 USA 201 475 4600 telephone receptionist, 8.30 - 5 pm EST. 201 475 4659 direct line w/voice mail, 24 hrs. 201 475 4677 fax, 24 hrs. >>> 17-Dec-01 7:30:45 AM >>> This particular labeling of "Nut" products is not an isolated event. Pick up viturally any container of mixed nuts and it will have a similar warning. Of course don't start reading too many food labels, it can get really scary. FDA's Food Alergen page is: http://www.fda.gov/ora/compliance_ref/cpg/cpgfod/cpg555-250.htm And you thought product safety standards were convoluted and political driven! We won't discuss the pages that address the standards for" "a. Insect Filth and Mold . . . contains an average of 1% or more insect infested and/or moldy pieces by weight. or b. Mammalian Excreta . . . contains an average of 1 milligram or more of mammalian excreta per pound. or c. Foreign Matter . . . contains an average of 1% or more pickings and siftings by weight, (What exactly is "Foreign Matter?) "The following represents the criteria for direct reference seizure: Insect Filth . . . contains an average of 100 or more insect fragments per 25 grams Rodent Filth . . . contains an average of 4 or more rodent hairs per 25 grams." and this is before it gets to the minimum wage food preparation specialist. "Do you want fries with that?" "Robert Macy" on 12/14/2001 04:39:16 PM Please respond to "Robert Macy" To: "James Collum" , emc-pstc%majordomo.ieee@interlock.lexmark.com cc:(bcc: Oscar Overton/Lex/Lexmark) Subject: Re: Sometimes product safety just isn't enough --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: 2 Phases in North America
Mike, I don't go with you on this one... 0 implies nothing ( prehaps 0 ac ) ... therefore the "0th" harmonic is dc??? if a squarewave is made up of "odd" harmonics, we would have to rethink that, correct? Derek. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Does anyone have an EMCO 7140?
Group, We are looking for an EMCO model 7140 which is a Fiber Optic to RS-232 converter for their Isotropic probes models 7120, 7121, etc. If any knows of one please contact me directly, I have tried the usual routes of used equipment and contacting EMC Test Systems directly, currently without luck. Thanks. Larry K. Stillings Compliance Worldwide, Inc. 357 Main Street Sandown, NH 03873 (603) 887 3903 Fax 887-6445 www.complianceworldwide.com Privileged/Confidential Information may be contained in this message. If you are not the addressee indicated in this message (or responsible for delivery of the message to such person), you may not copy or deliver this message to anyone. In such case, you should destroy this message and kindly notify the sender by reply email. Please advise immediately if you or your employer do not consent to Internet email for messages of this kind. Opinions, conclusions and other information in this message that do not relate to the official business of my firm shall be understood as neither given nor endorsed by it. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: Sometimes product safety just isn't enough
-Original Message-
From: James Collum [mailto:james.col...@usa.alcatel.com]
Sent: Friday, December 14, 2001 1:29 PM
To: emc-p...@majordomo.ieee.org
Subject: Re: Sometimes product safety just isn't enough
Following a recent airline flight, I was given a bag of peanuts, marked
"Peanuts" which contained a health warning "contains peanuts".
I was thinking that in a similar style that maybe electrical products could
have an added warning "may contain electricity".
The "may" would elude to the connection of a mains cable for mains powered
equipment, or even batteries in battery powered equipment. I think the IEC
should be prompt to act in this vital area.
Following this illogical train of thought, the swimming pool should have a
warning "contains water" and the ladder could have a warning "may alter
altitude".
But on a slightly more serious note (but not much) If I am ever present when
someone is about to do something interesting with electricity I always
advise that the person about to do the deed make sure to note who present
will provide the "kiss of life" when it all goes pear shaped. It tends to
work (although I don't know why, as I think I'm very kissable).
Jim
Which reminds me of an incident of mis-communication which happened when I
arrived home one rainy afternoon. As I parked my car, I observed my
neighbor's 11 yo boy climbing to the top of a tree in their yard. The tree
was located in the "utility easement", and had grown so tall that the
branches actually were higher than the three powerlines. (Yes, the 3-wire
single phase, 120-0-120 VAC; I just had to add that from another thread.
) As I looked at him, he was reaching over his head, trying to climb past
the level of the wires! And he was standing in a damp tree during a light
rain.
Sometimes you may worry that a sharp warning might cause an accident, but I
shouted to him that those wires were dangerous and to not climb any higher.
He replied that he was safe because he knew how to climb a tree. (My
neighbor, let us say, has raised a crop of dim bulbs.) I shouted to him that
both of those wires were hot, that the tree was grounded, and since he was
in the wet tree, he was grounded. Most logical.
Well, he didn't reply, but sullenly started down the tree. I went inside,
but my phone range a couple of minutes later. It was his mother, asking what
I had said to her son. When I told her, she laughed and said that her son
had complained that "nobody but his father could tell him that he was
grounded!" ("Grounded" is a state of social restriction used as a punishment
by American parents.)
Regards,
Ed
(who has a long history of being grounded)
Ed Price
ed.pr...@cubic.com
Electromagnetic Compatibility Lab
Cubic Defense Systems
San Diego, CA USA
858-505-2780 (Voice)
858-505-1583 (Fax)
Military & Avionics EMC Services Is Our Specialty
Shake-Bake-Shock - Metrology - Reliability Analysis
RE: 2 Phases in North America
This could be interesting::; if 50/60 is the 0th, then 100/120 would be the 1st ?? Makes sense to me!! No harmonics of the fundamental frequency would be the 0th; and 1st harmonic would be at twice the fundamental frequency. (I know this is not the convention, but it seems logical: first harmonic is fundamental plus the fundamental (once); second is the fundamental plus the fundamental x 2, etc. ). I like it! Mike Hopkins Thermo KeyTek -Original Message- From: bogdan matoga [mailto:bogda...@pacbell.net] Sent: Sunday, December 16, 2001 8:03 PM To: Cortland Richmond Cc: Jayasinghe, Ryan; Robert Johnson; 'Barry Esmore'; 'EMC-PSTC Forum' Subject: Re: 2 Phases in North America Cortland: I always thought that 50 Hz or respectively 60 Hz was the "0-th" harmonic! Was I mistaken? (I would not be surprised!) (: -) !! Bogdan. Cortland Richmond wrote: > This is rather similar to asking what the first harmonic of the power line > frequency is. (grin!) > > Cortland > > "Jayasinghe, Ryan" wrote: > > > 180° out of phase? > > --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Three phase delta system in USA
I also learned, that there is a three-phase delta system in USA with 500 Vac per phase. One phase (L3) is earthed. Is this system very often used in USA? Is it correct information, that L3 is always earthed and not L1 or L2. Horst Haug -Ursprüngliche Nachricht- Von: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]Im Auftrag von Crabb, John Gesendet: Montag, 17. Dezember 2001 11:28 An: 'Bill Lawrence'; 'EMC-PSTC Forum' Betreff: RE: 2 Phases in North America Bill - you absolutely correct in describing the North American system as "single-phase, 3 wire". After all, that is how it is described in Annex V, Figure V.4 of IEC60950:1999 - and there is NO WAY that IEC TC74 could be wrong, is there ? (especially since the US committee must have voted yes, to include this change, the purpose of which was to educate those of us who weren't too clear on the subject). Fortunately I am on holiday (vacation) from tonight until January 3, so to all our readers, best wishes for the Christmas season, and a happy and prosperous 2002. John Crabb, Development Excellence (Product Safety) , NCR Financial Solutions Group Ltd., Kingsway West, Dundee, Scotland. DD2 3XX E-Mail :john.cr...@scotland.ncr.com Tel: +44 (0)1382-592289 (direct ). Fax +44 (0)1382-622243. VoicePlus 6-341-2289. -Original Message- From: Bill Lawrence [mailto:wlawr...@capecod.net] Sent: 14 December 2001 22:33 To: 'Wagner, John P (John)'; 'Robert Johnson'; 'Cortland Richmond' Cc: 'Barry Esmore'; 'EMC-PSTC Forum' Subject: RE: 2 Phases in North America Two Phase / 5 Wire (4 "hots" and a neutral) was a common power distribution in US cities in the early part of this century. Many early motors are "2-phase" motors. I learned about this when helping with connection of these motors to run on a 3 phase power system via a special "Scott-T" transformer connection. The correct designation for the 120/240 power system described is "Single Phase / 3 Wire". Bill Lawrence
Re: Regulatory General Discussion : ouput of Compliance group
I read in !emc-pstc that Andre, Pierre-Marie wrote (in <9985493A802AD5118C4E0090274627535EC2EE @swsmsx34.isw.intel.com>) about 'Regulatory General Discussion : ouput of Compliance group', on Mon, 17 Dec 2001: >The good argument is really in the FULL implication of the Compliance group >in the design process right ? with full power to sign off the design changes IMHO, the European EMC and Low Voltage Directives effectively require this to be the case. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk After swimming across the Hellespont, I felt like a Hero. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: Sometimes product safety just isn't enough
This particular labeling of "Nut" products is not an isolated event. Pick up viturally any container of mixed nuts and it will have a similar warning. Of course don't start reading too many food labels, it can get really scary. FDA's Food Alergen page is: http://www.fda.gov/ora/compliance_ref/cpg/cpgfod/cpg555-250.htm And you thought product safety standards were convoluted and political driven! We won't discuss the pages that address the standards for" "a. Insect Filth and Mold . . . contains an average of 1% or more insect infested and/or moldy pieces by weight. or b. Mammalian Excreta . . . contains an average of 1 milligram or more of mammalian excreta per pound. or c. Foreign Matter . . . contains an average of 1% or more pickings and siftings by weight, (What exactly is "Foreign Matter?) "The following represents the criteria for direct reference seizure: Insect Filth . . . contains an average of 100 or more insect fragments per 25 grams Rodent Filth . . . contains an average of 4 or more rodent hairs per 25 grams." and this is before it gets to the minimum wage food preparation specialist. "Do you want fries with that?" "Robert Macy" on 12/14/2001 04:39:16 PM Please respond to "Robert Macy" To: "James Collum" , emc-pstc%majordomo.ieee@interlock.lexmark.com cc:(bcc: Oscar Overton/Lex/Lexmark) Subject: Re: Sometimes product safety just isn't enough In deference to the warning label on the peanuts bag. Some people have life threatening allergies to peanuts and take warnings such as that and warnings on cookies, etc very seriously. But then again, you'd think with the main label "Peanuts" would be sufficient. Perhaps, someone is making peanuts out of soy beans already. - Robert - Robert A. Macy, PEm...@california.com 408 286 3985 fx 408 297 9121 AJM International Electronics Consultants 619 North First St, San Jose, CA 95112 -Original Message- From: James Collum To: emc-p...@majordomo.ieee.org List-Post: emc-pstc@listserv.ieee.org Date: Friday, December 14, 2001 1:57 PM Subject: Re: Sometimes product safety just isn't enough Following a recent airline flight, I was given a bag of peanuts, marked "Peanuts" which contained a health warning "contains peanuts". I was thinking that in a similar style that maybe electrical products could have an added warning "may contain electricity". The "may" would elude to the connection of a mains cable for mains powered equipment, or even batteries in battery powered equipment. I think the IEC should be prompt to act in this vital area. Following this illogical train of thought, the swimming pool should have a warning "contains water" and the ladder could have a warning "may alter altitude". But on a slightly more serious note (but not much) If I am ever present when someone is about to do something interesting with electricity I always advise that the person about to do the deed make sure to note who present will provide the "kiss of life" when it all goes pear shaped. It tends to work (although I don't know why, as I think I'm very kissable). Jim -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of Robert Johnson Sent: woensdag 12 december 2001 19:28 To: emc-p...@majordomo.ieee.org Subject: Sometimes product safety just isn't enough I couldnââ� â ä¢t help passing on this reference to a bit of unforeseeable misuse. http://electrical-contractor.net/ubb/Forum4/HTML/48.html Bob Johnson --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: Regulatory General Discussion : ouput of Compliance group
Doug, thanks you for your inputs. The good argument is really in the FULL implication of the Compliance group in the design process right ? with full power to sign off the design changes best regards to all compliance engineers Pierre-Marie Andre Senior Approval Engineer -Original Message- From: Doug McKean [mailto:dmck...@auspex.com] Sent: samedi 15 décembre 2001 01:26 To: EMC-PSTC Discussion Group Subject: Re: Regulatory General Discussion : ouput of Compliance group "Andre, Pierre-Marie" wrote: > > So has anybody some thoughts or argument on the measurement > or evaluation of an Compliance Group ? Well, I'd hate to let the dirty little secret out of the bag for those of us who would fall under such and evaluation. Important in such an evaluation would be that the company has allowed the compliance engineer to have significant input to the design/mfring processes. I've been in companies where evaluations from the compliance engineer amounted to nothing more than a suggestion. Very frustrating. Other places had the compliance engineer greatly involved as a signatory in product release and with ECR/ECOs. Start with an ideal world where the compliance engineer has complete planning, budgeting, signatory/approval powers with the complete product cycle from prototype-to-product release-to product obsolescence. Consider that as the complete model. Then, as the person has less and less involvement/approval power in those areas, they are thus less responsible for them and thus, they are not to be evaluated in those areas. You'll probably find the typical compliance engineer ends up in reality scheduling tests w/no approval powers, has input to ECR/ECOs but no signatory powers, inputs into product design by way of memos, sometimes are the last to know about significant design changes, and might answer to someone who knows little about compliance engineering. IMO, evaluation would be difficult. Regards, Doug McKean --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: 2 Phases in North America
Bill - you absolutely correct in describing the North American system as "single-phase, 3 wire". After all, that is how it is described in Annex V, Figure V.4 of IEC60950:1999 - and there is NO WAY that IEC TC74 could be wrong, is there ? (especially since the US committee must have voted yes, to include this change, the purpose of which was to educate those of us who weren't too clear on the subject). Fortunately I am on holiday (vacation) from tonight until January 3, so to all our readers, best wishes for the Christmas season, and a happy and prosperous 2002. John Crabb, Development Excellence (Product Safety) , NCR Financial Solutions Group Ltd., Kingsway West, Dundee, Scotland. DD2 3XX E-Mail :john.cr...@scotland.ncr.com Tel: +44 (0)1382-592289 (direct ). Fax +44 (0)1382-622243. VoicePlus 6-341-2289. -Original Message- From: Bill Lawrence [mailto:wlawr...@capecod.net] Sent: 14 December 2001 22:33 To: 'Wagner, John P (John)'; 'Robert Johnson'; 'Cortland Richmond' Cc: 'Barry Esmore'; 'EMC-PSTC Forum' Subject: RE: 2 Phases in North America Two Phase / 5 Wire (4 "hots" and a neutral) was a common power distribution in US cities in the early part of this century. Many early motors are "2-phase" motors. I learned about this when helping with connection of these motors to run on a 3 phase power system via a special "Scott-T" transformer connection. The correct designation for the 120/240 power system described is "Single Phase / 3 Wire". Bill Lawrence
Re: 2 Phases in North America
If we're smart (are we?) we'll say "fundamental," and let whoever wants to argue what "2nd" means have the arena all to themselves! I would say there are harmonics of the second order, third order, and so on, to which we refer, in short, as the second and third harmonics (and so on). Don't forget, though, where the terms came from; what IS harmonic motion, hmm? Cortland --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
working voltage measurement
Hi Group I have a question regarding working voltage measurement of IEC 60950 we have a E.U.T.(switching power supply) I want to clarify the measurement of working voltage 1. Using an oscilloscope having an adequate bandwith and using a high impedance probe (100Mohm), and adequate integration time to measure working voltage. The load on the secondary circuits is to be varied in order to find highest voltage across the insulation. Floating secondary outputs (capacitively connected to earth) are earthed. 2. don't make connection between primary winding and secondary winding. 3. we will get a stable waveform on the oscilloscope. working voltage we measure are as follows: The waveform we get by the above method is a kind of waveform modulated by high-frequency switching waveform. MEASURED voltage: 246V(rms),576V(peak) When we change trigger level and time base to obtain stable switching waveform, we get different rms voltage with different trigger level. the highest rms voltage we get is 380V. My question 1. the above steps are correct or not? 2. For switching power supply, what waveform of working voltage is correct for primary and secondary How to obtain? 3. Which one(246V, 380V) is correct for working voltage measurement? or other methods? Thank you for any comments in advance Best Regards Xing weibing 2001-12-17
Re: 2 Phases in North America
Cortland: I always thought that 50 Hz or respectively 60 Hz was the "0-th" harmonic! Was I mistaken? (I would not be surprised!) (: -) !! Bogdan. Cortland Richmond wrote: > This is rather similar to asking what the first harmonic of the power line > frequency is. (grin!) > > Cortland > > "Jayasinghe, Ryan" wrote: > > > 180° out of phase? > > --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
